Graphs and charts are used extensively in business, industry and academe, as well as in the home, to graphically represent many different kinds of data and a wide diversity of situations and relationships. The information to be presented is often of a dynamic nature, requiring that changes be made from time to time if an accurate representation is to be maintained. Frequently however, only part of the graph or chart is to be revised, and it is therefore highly desirable for such a display to offer the capability of quick and easy rearrangement and alteration, while also enabling previously established graphic features to be preserved and updated. As indicated by the following U.S. patents, the prior art fails to do so in an optimal manner:
Wagner U.S. Pat. No. 2,305,047 shows a display sign constructed from an array of cubic glass blocks or other building elements, some of which are provided with angled carrier members to form a ledge for supporting sign letters.
U.S. Pat. No. 2,544,445, to Corzilius, provides a production control board which utilizes a set of stacked strips, each having a dovetail groove to receive a row of inserts.
Gauge elements, which may be of different lengths, are received in parallel slots of the graphical chart display board shown in Mendell U.S. Pat. No. 3,124,885.
In accordance with McVicker et al U.S. Pat. No. 3,419,979, a number of board units are assembled alongside one another in a supporting frame to provide a pattern of parallel ribs; small plastic markers having opposed legs are snapped over the ribs to form columns, and they are described to be slidable therealong and readily removed therefrom.
Jimenez U.S. Pat. No. 3,458,944 discloses a sign construction consisting of numerous transparent plastic pockets arranged in a rectangular array on a panel, the pockets being adapted to receive inserts placed so as to form sign characters.
A visual display device, consisting of hinged panels, is provided by Bytwork U.S. Pat. No. 3,755,938; at least one of the panels has "magnetizable sheet means" secured to its inside surface, to cooperate with magnetic display members.
Kane U.S. Pat. No. 4,654,101 discloses a method for making a changeable display sign; a magnetic support is employed for securing flexible sign component pieces, the latter having undercut marginal edges to promote close interfitting.
Van Erum U.S. Pat. No. 4,669,210 provides a supporting board that is formed with horizontal "clip strips" having grooved lateral sides; cooperating plates, which may or may not be character bearing, have resilient legs for snapping into the grooves.
Accordingly, it is the broad object of the present invention to provide a novel graphical display system comprising a base board of readily variable extent, and display-forming pieces that are readily engaged upon and disengaged from the base board, and that are readily shifted thereover to different positions.
A more specific object of the invention is to provide such a system wherein a plurality of cover pieces of differing structural characteristics are employed, which pieces are adapted for assembly on the base board in a variety of arrangements so as to afford unique graphical display effects.
Additional objects of the invention are to provide such a graphical display system which is easy and convenient to utilize, is relatively uncomplicated and inexpensive to manufacture, and is adapted to provide graphical displays, such as for charts, graphs, and schedules, that are highly attractive and of strong visual impact.